We will continue our investigation of the origin and metabolic fate of taurine in heart and brain. This shall include (1) the biosynthesis of taurine from cysteine sulfinate (2) the desulfination of cysteinsulfinate (3) the metabolism of hypotaurine (4) the biosynthesis of isethionate. We are also developing a sensitive gas chromatographic method for the determination of taurine and hypotaurine with derivatives detectable with an electron capture detector.